process.cc revision 2665:a124942bacb8 
1/*
2 * Copyright (c) 2001-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Nathan Binkert
29 *          Steve Reinhardt
30 *          Ali Saidi
31 */
32
33#include <unistd.h>
34#include <fcntl.h>
35
36#include <string>
37
38#include "base/intmath.hh"
39#include "base/loader/object_file.hh"
40#include "base/loader/symtab.hh"
41#include "base/statistics.hh"
42#include "config/full_system.hh"
43#include "cpu/exec_context.hh"
44#include "mem/page_table.hh"
45#include "mem/physical.hh"
46#include "mem/translating_port.hh"
47#include "sim/builder.hh"
48#include "sim/process.hh"
49#include "sim/stats.hh"
50#include "sim/syscall_emul.hh"
51#include "sim/system.hh"
52
53using namespace std;
54using namespace TheISA;
55
56//
57// The purpose of this code is to fake the loader & syscall mechanism
58// when there's no OS: thus there's no resone to use it in FULL_SYSTEM
59// mode when we do have an OS
60//
61#if FULL_SYSTEM
62#error "process.cc not compatible with FULL_SYSTEM"
63#endif
64
65// current number of allocated processes
66int num_processes = 0;
67
68Process::Process(const string &nm,
69                 System *_system,
70                 int stdin_fd, 	// initial I/O descriptors
71                 int stdout_fd,
72                 int stderr_fd)
73    : SimObject(nm), system(_system)
74{
75    // initialize first 3 fds (stdin, stdout, stderr)
76    fd_map[STDIN_FILENO] = stdin_fd;
77    fd_map[STDOUT_FILENO] = stdout_fd;
78    fd_map[STDERR_FILENO] = stderr_fd;
79
80    // mark remaining fds as free
81    for (int i = 3; i <= MAX_FD; ++i) {
82        fd_map[i] = -1;
83    }
84
85    mmap_start = mmap_end = 0;
86    nxm_start = nxm_end = 0;
87    pTable = new PageTable(system);
88    // other parameters will be initialized when the program is loaded
89}
90
91
92void
93Process::regStats()
94{
95    using namespace Stats;
96
97    num_syscalls
98        .name(name() + ".PROG:num_syscalls")
99        .desc("Number of system calls")
100        ;
101}
102
103//
104// static helper functions
105//
106int
107Process::openInputFile(const string &filename)
108{
109    int fd = open(filename.c_str(), O_RDONLY);
110
111    if (fd == -1) {
112        perror(NULL);
113        cerr << "unable to open \"" << filename << "\" for reading\n";
114        fatal("can't open input file");
115    }
116
117    return fd;
118}
119
120
121int
122Process::openOutputFile(const string &filename)
123{
124    int fd = open(filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0774);
125
126    if (fd == -1) {
127        perror(NULL);
128        cerr << "unable to open \"" << filename << "\" for writing\n";
129        fatal("can't open output file");
130    }
131
132    return fd;
133}
134
135
136int
137Process::registerExecContext(ExecContext *xc)
138{
139    // add to list
140    int myIndex = execContexts.size();
141    execContexts.push_back(xc);
142
143    // return CPU number to caller
144    return myIndex;
145}
146
147void
148Process::startup()
149{
150    if (execContexts.empty())
151        fatal("Process %s is not associated with any CPUs!\n", name());
152
153    // first exec context for this process... initialize & enable
154    ExecContext *xc = execContexts[0];
155
156    // mark this context as active so it will start ticking.
157    xc->activate(0);
158
159    Port *mem_port;
160    mem_port = system->physmem->getPort("functional");
161    initVirtMem = new TranslatingPort("process init port", pTable, true);
162    mem_port->setPeer(initVirtMem);
163    initVirtMem->setPeer(mem_port);
164}
165
166void
167Process::replaceExecContext(ExecContext *xc, int xcIndex)
168{
169    if (xcIndex >= execContexts.size()) {
170        panic("replaceExecContext: bad xcIndex, %d >= %d\n",
171              xcIndex, execContexts.size());
172    }
173
174    execContexts[xcIndex] = xc;
175}
176
177// map simulator fd sim_fd to target fd tgt_fd
178void
179Process::dup_fd(int sim_fd, int tgt_fd)
180{
181    if (tgt_fd < 0 || tgt_fd > MAX_FD)
182        panic("Process::dup_fd tried to dup past MAX_FD (%d)", tgt_fd);
183
184    fd_map[tgt_fd] = sim_fd;
185}
186
187
188// generate new target fd for sim_fd
189int
190Process::alloc_fd(int sim_fd)
191{
192    // in case open() returns an error, don't allocate a new fd
193    if (sim_fd == -1)
194        return -1;
195
196    // find first free target fd
197    for (int free_fd = 0; free_fd < MAX_FD; ++free_fd) {
198        if (fd_map[free_fd] == -1) {
199            fd_map[free_fd] = sim_fd;
200            return free_fd;
201        }
202    }
203
204    panic("Process::alloc_fd: out of file descriptors!");
205}
206
207
208// free target fd (e.g., after close)
209void
210Process::free_fd(int tgt_fd)
211{
212    if (fd_map[tgt_fd] == -1)
213        warn("Process::free_fd: request to free unused fd %d", tgt_fd);
214
215    fd_map[tgt_fd] = -1;
216}
217
218
219// look up simulator fd for given target fd
220int
221Process::sim_fd(int tgt_fd)
222{
223    if (tgt_fd > MAX_FD)
224        return -1;
225
226    return fd_map[tgt_fd];
227}
228
229
230
231//
232// need to declare these here since there is no concrete Process type
233// that can be constructed (i.e., no REGISTER_SIM_OBJECT() macro call,
234// which is where these get declared for concrete types).
235//
236DEFINE_SIM_OBJECT_CLASS_NAME("Process", Process)
237
238
239////////////////////////////////////////////////////////////////////////
240//
241// LiveProcess member definitions
242//
243////////////////////////////////////////////////////////////////////////
244
245
246void
247copyStringArray(vector<string> &strings, Addr array_ptr, Addr data_ptr,
248                TranslatingPort* memPort)
249{
250    Addr data_ptr_swap;
251    for (int i = 0; i < strings.size(); ++i) {
252        data_ptr_swap = htog(data_ptr);
253        memPort->writeBlob(array_ptr, (uint8_t*)&data_ptr_swap, sizeof(Addr));
254        memPort->writeString(data_ptr, strings[i].c_str());
255        array_ptr += sizeof(Addr);
256        data_ptr += strings[i].size() + 1;
257    }
258    // add NULL terminator
259    data_ptr = 0;
260
261    memPort->writeBlob(array_ptr, (uint8_t*)&data_ptr, sizeof(Addr));
262}
263
264LiveProcess::LiveProcess(const string &nm, ObjectFile *_objFile,
265                         System *_system,
266                         int stdin_fd, int stdout_fd, int stderr_fd,
267                         vector<string> &_argv, vector<string> &_envp)
268    : Process(nm, _system, stdin_fd, stdout_fd, stderr_fd),
269      objFile(_objFile), argv(_argv), envp(_envp)
270{
271    prog_fname = argv[0];
272
273    // load up symbols, if any... these may be used for debugging or
274    // profiling.
275    if (!debugSymbolTable) {
276        debugSymbolTable = new SymbolTable();
277        if (!objFile->loadGlobalSymbols(debugSymbolTable) ||
278            !objFile->loadLocalSymbols(debugSymbolTable)) {
279            // didn't load any symbols
280            delete debugSymbolTable;
281            debugSymbolTable = NULL;
282        }
283    }
284}
285
286void
287LiveProcess::argsInit(int intSize, int pageSize)
288{
289    Process::startup();
290
291    // load object file into target memory
292    objFile->loadSections(initVirtMem);
293
294    // Calculate how much space we need for arg & env arrays.
295    int argv_array_size = intSize * (argv.size() + 1);
296    int envp_array_size = intSize * (envp.size() + 1);
297    int arg_data_size = 0;
298    for (int i = 0; i < argv.size(); ++i) {
299        arg_data_size += argv[i].size() + 1;
300    }
301    int env_data_size = 0;
302    for (int i = 0; i < envp.size(); ++i) {
303        env_data_size += envp[i].size() + 1;
304    }
305
306    int space_needed =
307        argv_array_size + envp_array_size + arg_data_size + env_data_size;
308    // for SimpleScalar compatibility
309    if (space_needed < 16384)
310        space_needed = 16384;
311
312    // set bottom of stack
313    stack_min = stack_base - space_needed;
314    // align it
315    stack_min &= ~(intSize-1);
316    stack_size = stack_base - stack_min;
317    // map memory
318    pTable->allocate(roundDown(stack_min, pageSize),
319                     roundUp(stack_size, pageSize));
320
321    // map out initial stack contents
322    Addr argv_array_base = stack_min + intSize; // room for argc
323    Addr envp_array_base = argv_array_base + argv_array_size;
324    Addr arg_data_base = envp_array_base + envp_array_size;
325    Addr env_data_base = arg_data_base + arg_data_size;
326
327    // write contents to stack
328    uint64_t argc = argv.size();
329    if (intSize == 8)
330        argc = htog((uint64_t)argc);
331    else if (intSize == 4)
332        argc = htog((uint32_t)argc);
333    else
334        panic("Unknown int size");
335
336    initVirtMem->writeBlob(stack_min, (uint8_t*)&argc, intSize);
337
338    copyStringArray(argv, argv_array_base, arg_data_base, initVirtMem);
339    copyStringArray(envp, envp_array_base, env_data_base, initVirtMem);
340
341    execContexts[0]->setIntReg(ArgumentReg0, argc);
342    execContexts[0]->setIntReg(ArgumentReg1, argv_array_base);
343    execContexts[0]->setIntReg(StackPointerReg, stack_min);
344
345    Addr prog_entry = objFile->entryPoint();
346    execContexts[0]->setPC(prog_entry);
347    execContexts[0]->setNextPC(prog_entry + sizeof(MachInst));
348    execContexts[0]->setNextNPC(prog_entry + (2 * sizeof(MachInst)));
349
350    num_processes++;
351}
352
353void
354LiveProcess::syscall(int64_t callnum, ExecContext *xc)
355{
356    num_syscalls++;
357
358    SyscallDesc *desc = getDesc(callnum);
359    if (desc == NULL)
360        fatal("Syscall %d out of range", callnum);
361
362    desc->doSyscall(callnum, this, xc);
363}
364
365DEFINE_SIM_OBJECT_CLASS_NAME("LiveProcess", LiveProcess);
366